Giovanni Lanaro was born in Los Angeles, grew up in La Puente, attended Cal State Fullerton, and coaches and trains at Mt. San Antonio College. Yet, when the torch is lighted during opening ceremonies this summer at the Beijing Olympics, the world's sixth-ranked pole vaulter will be with Mexico, not the United States.

"I will always compete for Mexico," said Lanaro, whose mother was born there. "I will never compete for any other country."

He is hardly alone in choosing to compete for the land of his heritage over the place of his birth -- a growing practice in recent years as the Mexican American population has surged past 28 million, swelling the eligible talent pool that Mexican sports officials have tapped occasionally.

Five of the nine boxers on Mexico's national team are from the U.S., as are a wrestler, a women's basketball player and two members of last summer's Pan American Games water polo team.

"My whole family's proud. What's wrong with being proud about competing for Mexico?" said Lanaro, who has cleared 19 feet this year and is Mexico's best hope for a track and field medal in Beijing. "I don't see anything wrong with it."

Others are critical, however, with those in the U.S. arguing that American athletes who compete for Mexico are turning their back on the country that trained them in exchange for an easier path to the Olympics. And in Mexico, some coaches and athletes have grown tired of "foreigners" taking opportunities away from locals.

"In my opinion, yes, it's controversial, a little unethical," said German Silva, a two-time Olympian and now a top Mexican distance-running coach.

But it is legal. In fact, top athletes crossing borders to enhance their Olympic prospects are part of a well-established pattern that involves many nations and events. Four years ago at Athens, Americans of Greek descent took the field for the host nation's baseball team, a Chinese-born table tennis player competed for the United States and a Jamaican woman sprinted for Slovenia.

"Freedom of choice is one of the values our country stands for," said Darryl Seibel, chief communications officer of the U.S. Olympic Committee. "And we're not going to stand in the way of someone who wants to compete for another country."

The U.S. has also benefited from foreign-born athletes changing allegiances: 1,500-meter runner Bernard Lagat and marathoner Khalid Khannouchi were born in Africa, yet now hold U.S. records. And national gymnastics champions Nastia Liukin and Alexander Artemev are from the former Soviet Union.

The U.S. rules are stricter than most, though, requiring that Olympians hold American citizenship. Mexico, reflecting the practice of many nations, welcomes athletes who may have been born or reared elsewhere but are of Mexican descent.

That has opened the door for Lanaro and fellow vaulter Robison Pratt, who was born in Saudi Arabia to a family with ties to Mexico dating to before the Mexican Revolution.

Although Pratt's first language is English, he has a degree from Brigham Young University, he lives in Chino Hills and distant cousin Mitt Romney campaigned for the Republican presidential nomination, Pratt wore a Mexican uniform at the 2000 Sydney Games.

"I could have gone either direction," said Pratt, who will miss the Beijing Games because of a knee injury. "I'm comfortable with both cultures. I'm comfortable with both languages. I'm comfortable with a Mexican uniform on."

The government ministry that oversees international sports in Mexico has tried to straddle the controversy, alternately reaching out to Mexican American athletes, then bowing to internal pressure by going mum on the subject while allowing individual sports federations to do their own recruiting.

"There still is some resistance by some of the authorities to Mexican Americans," said Elbert Pratt, Robison's father and a track coach at Monterrey Tech, one of Mexico's leading universities. "But my position is, if they're Mexican citizens or their parents were Mexican citizens, they have a constitutional right. They have the same right as anybody."

In an example of this friction, Pratt recruited DePaul University shot putter Frank Guzman in 2003 to try out for Mexico's Pan American Games team. To qualify, Guzman had to compete in a meet in Mexico. But three athletes must take part in a competition to make it legal, and a Mexican shot putter whose spot on the team was threatened by Guzman organized a boycott of the meet to deny the American a chance.

Pratt eventually rounded up two local teenagers and, after a delay of more than an hour, Guzman threw, breaking the Mexican record by 9 feet.

"The guy's point was, 'I've been working for years, and now this guy shows up and just wins it,' " Pratt said about the athlete who organized the boycott. "Hey, Guzman had been working for years too. This isn't about who has the most right to go because of the number of years they've worked. This is about who is the very best."

Lanaro also got a cold shoulder when Pratt invited him to compete for Mexico. But since shattering the national record and representing Mexico in four world championships, two Pan-Am Games and the Athens Olympics, that resistance has faded.

"They all know we live [in the United States] and we have better resources than what they do," Lanaro said. "But the bottom line is, I compete for that country. Whether I'm here, there, it doesn't matter. I represent the country."

Lanaro says most of the criticism he gets now comes from people in the U.S.

"It's all stupid. It's ridiculous," said Lanaro, who contacted the Mexican team with help from his girlfriend, a high jumper from Culiacan. "I'm not sitting here in the United States of America waving around a Mexican flag. If I am proud competing for my country, people need to respect that."

Lanaro, whose marks are good enough to make him a contender for the U.S. Olympic team, concedes the fact that not having to negotiate a cutthroat qualifying meet to go to Beijing makes competing for Mexico appealing. But he insists that had little to do with his decision.

"I never thought I'd be this good, first off. I never thought I'd reach this level," said Lanaro, whose best vault in high school was just 11 feet, 6 inches. "And when I did, I said well, I'd like to compete for Mexico. So I did."

There's no disputing that the border crossings have helped raised the level of sport in Mexico.

"If you bring in people with other experiences and perhaps people that are more developed and further along in their sport, it's definitely going to add," said Larry Langowski, a former wrestler at Northwestern who became part of the Mexican team four years ago after asking local officials if there was a place he could train while visiting relatives in Mexico City. "You want the best talent. Bringing in the best breeds better people."

But although some national programs -- such as women's soccer and boxing -- aggressively seek U.S. residents for their teams, it typically falls to the athlete to make the first move.

Basketball player Jennifer Arriola Vucovich, who joined the Mexican national team after playing in college at Texas Pan American, wasn't recruited until she enrolled at Monterrey Tech to pursue a master's degree in biotechnology three years ago.

"To participate in the U.S. national team, I would have to dedicate most of my time to just training and playing basketball," said Vucovich, who was born in Arizona to parents from Sonora, Mexico.

She said being on Mexico's team allows her to have time for studying and her sport "without having to choose one or the other."

Mexico may again be moving toward organized recruiting of U.S.-born athletes. Langowski brought up the idea when he and other Mexican Olympians met with President Felipe Calderon recently. He said he found the president and First Lady Margarita Zavala receptive.

"It's going to keep happening," said Lanaro, who is an assistant coach at Mt. San Antonio College in Walnut, where he vaulted after graduating from West Covina High.

"There are a lot of people coming to the U.S. and a lot of kids will be born in the U.S., and a lot of people will still go and compete for other countries."